/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdio.h>
#include <stdlib.h>
#include "unistd.h"
#include <string.h>
#include <errno.h>
#include <tchar.h>
#include "sysdeps.h"

#define   TRACE_TAG  TRACE_TRANSPORT
#include "adb.h"

static void transport_unref(atransport *t);

static atransport transport_list = {
	&transport_list,
	&transport_list,
};

ADB_MUTEX_DEFINE( transport_lock );

#if ADB_TRACE
#define MAX_DUMP_HEX_LEN 16
static void  dump_hex( const unsigned char*  ptr, size_t  len )
{
	int  nn, len2 = len;
	// Build a string instead of logging each character.
	// MAX chars in 2 digit hex, one space, MAX chars, one '\0'.
	char buffer[MAX_DUMP_HEX_LEN *2 + 1 + MAX_DUMP_HEX_LEN + 1 ], *pb = buffer;

	if (len2 > MAX_DUMP_HEX_LEN) len2 = MAX_DUMP_HEX_LEN;

	for (nn = 0; nn < len2; nn++) {
		sprintf(pb, "%02x", ptr[nn]);
		pb += 2;
	}
	sprintf(pb++, " ");

	for (nn = 0; nn < len2; nn++) {
		int  c = ptr[nn];
		if (c < 32 || c > 127)
			c = '.';
		*pb++ =  c;
	}
	*pb++ = '\0';
	DR("%s\n", buffer);
}
#endif

void kick_transport(atransport*  t)
{
	if (t && !t->kicked)
	{
		int  kicked;

		adb_mutex_lock(&transport_lock);
		kicked = t->kicked;
		if (!kicked)
			t->kicked = 1;
		adb_mutex_unlock(&transport_lock);

		if (!kicked)
			t->kick(t);
	}
}

void run_transport_disconnects(atransport*  t)
{
	adisconnect*  dis = t->disconnects.next;

	D("%s: run_transport_disconnects\n", t->serial);
	while (dis != &t->disconnects) {
		adisconnect*  next = dis->next;
		dis->func( dis->opaque, t );
		dis = next;
	}
}

#if ADB_TRACE
static void dump_packet(const char* name, const char* func, apacket* p)
{
	unsigned  command = p->msg.command;
	int       len     = p->msg.data_length;
	char      cmd[9];
	char      arg0[12], arg1[12];
	int       n;

	for (n = 0; n < 4; n++) {
		int  b = (command >> (n*8)) & 255;
		if (b < 32 || b >= 127)
			break;
		cmd[n] = (char)b;
	}
	if (n == 4) {
		cmd[4] = 0;
	} else {
		/* There is some non-ASCII name in the command, so dump
		 * the hexadecimal value instead */
		sprintf(cmd, "%08x", command);

	}

	if (p->msg.arg0 < 256U)
		sprintf(arg0, "%d", p->msg.arg0);

	else
		sprintf(arg0, "0x%x", p->msg.arg0);

	if (p->msg.arg1 < 256U)
		sprintf(arg1,  "%d", p->msg.arg1);

	else
		sprintf(arg1,  "0x%x", p->msg.arg1);

	D("%s: %s: [%s] arg0=%s arg1=%s (len=%d) ",
			name, func, cmd, arg0, arg1, len);
	dump_hex(p->data, len);
}
#endif /* ADB_TRACE */

static int read_packet(int  fd, const char* name, apacket** ppacket)
{
	char *p = (char*)ppacket;  /* really read a packet address */
	int   r;
	int   len = sizeof(*ppacket);
	char  buff[8];

	if (!name) {
		sprintf(buff, "fd=%d", fd);
		name = buff;
	}
	while(len > 0) {

		r = adb_read(fd, p, len);
		if(r > 0) {
			len -= r;
			p   += r;
		} else {
			D("%s: read_packet (fd=%d), error ret=%d errno=%d: %s\n", name, fd, r, errno, strerror(errno));
			if((r < 0) && (errno == EINTR)) continue;
			return -1;
		}
	}

#if ADB_TRACE
	if (ADB_TRACING) {
		dump_packet(name, "from remote", *ppacket);
	}
#endif
	return 0;
}

static int write_packet(int  fd, const char* name, apacket** ppacket)
{
	char *p = (char*) ppacket;  /* we really write the packet address */
	int r, len = sizeof(ppacket);
	char buff[8];
	if (!name) {
		sprintf(buff, "fd=%d", fd);
		name = buff;
	}

#if ADB_TRACE
	if (ADB_TRACING) {
		dump_packet(name, "to remote", *ppacket);
	}
#endif
	len = sizeof(ppacket);
	while(len > 0) {
		r = adb_write(fd, p, len);
		if(r > 0) {
			len -= r;
			p += r;
		} else {
			D("%s: write_packet (fd=%d) error ret=%d errno=%d: %s\n", name, fd, r, errno, strerror(errno));
			if((r < 0) && (errno == EINTR)) continue;
			return -1;
		}
	}
	return 0;
}

static void transport_socket_events(int fd, unsigned events, void *_t)
{
	atransport *t =(atransport *) _t;
	if(events & FDE_READ){
		apacket *p = 0;
		if(read_packet(fd, t->serial, &p)){
			D("%s: failed to read packet from transport socket on fd %d\n", t->serial, fd);

		} else {

			handle_packet(p, (atransport *) _t);
		}
	}
}

void send_packet(apacket *p, atransport *t)
{
	unsigned char *x;
	unsigned sum;
	unsigned count;

	p->msg.magic = p->msg.command ^ 0xffffffff;

	count = p->msg.data_length;
	x = (unsigned char *) p->data;
	sum = 0;
	while(count-- > 0){
		sum += *x++;
	}
	p->msg.data_check = sum;

	print_packet("send", p);

	if (t == NULL) {
		D("Transport is null \n");
		// Zap errno because print_packet() and other stuff have errno effect.
		errno = 0;
		fatal_errno("Transport is null");
	}

	if(write_packet(t->transport_socket, t->serial, &p)){
		fatal_errno("cannot enqueue packet on transport socket");
	}
}

/* The transport is opened by transport_register_func before
 ** the input and output threads are started.
 **
 ** The output thread issues a SYNC(1, token) message to let
 ** the input thread know to start things up.  In the event
 ** of transport IO failure, the output thread will post a
 ** SYNC(0,0) message to ensure shutdown.
 **
 ** The transport will not actually be closed until both
 ** threads exit, but the input thread will kick the transport
 ** on its way out to disconnect the underlying device.
 */

static void *output_thread(void *_t)
{
	atransport *t = (atransport *)_t;
	apacket *p;

	D("%s: starting transport output thread on fd %d, SYNC online (%d)\n",
			t->serial, t->fd, t->sync_token + 1);
	p = get_apacket();
	p->msg.command = A_SYNC;
	p->msg.arg0 = 1;
	p->msg.arg1 = ++(t->sync_token);
	p->msg.magic = A_SYNC ^ 0xffffffff;
	if(write_packet(t->fd, t->serial, &p)) {
		put_apacket(p);
		D("%s: failed to write SYNC packet\n", t->serial);
		goto oops;
	}

	D("%s: data pump started\n", t->serial);
	for(;;) {
		p = get_apacket();

		if(t->read_from_remote(p, t) == 0){
			D("%s: received remote packet, sending to transport\n",
					t->serial);
			if(write_packet(t->fd, t->serial, &p)){
				put_apacket(p);
				D("%s: failed to write apacket to transport\n", t->serial);
				goto oops;
			}
		} else {
			D("%s: remote read failed for transport\n", t->serial);
			put_apacket(p);
			break;
		}
	}

	D("%s: SYNC offline for transport\n", t->serial);
	p = get_apacket();
	p->msg.command = A_SYNC;
	p->msg.arg0 = 0;
	p->msg.arg1 = 0;
	p->msg.magic = A_SYNC ^ 0xffffffff;
	if(write_packet(t->fd, t->serial, &p)) {
		put_apacket(p);
		D("%s: failed to write SYNC apacket to transport", t->serial);
	}

oops:
	D("%s: transport output thread is exiting\n", t->serial);
	kick_transport(t);
	transport_unref(t);
	return 0;
}

static void *input_thread(void *_t)
{
	atransport *t =  (atransport *)_t;
	apacket *p;
	int active = 0;

	D("%s: starting transport input thread, reading from fd %d\n",
			t->serial, t->fd);

	for(;;){
		if(read_packet(t->fd, t->serial, &p)) {
			D("%s: failed to read apacket from transport on fd %d\n",
					t->serial, t->fd );
			break;
		}
		if(p->msg.command == A_SYNC){
			if(p->msg.arg0 == 0) {
				D("%s: transport SYNC offline\n", t->serial);
				put_apacket(p);
				break;
			} else {
				if(p->msg.arg1 == t->sync_token) {
					D("%s: transport SYNC online\n", t->serial);
					active = 1;
				} else {
					D("%s: transport ignoring SYNC %d != %d\n",
							t->serial, p->msg.arg1, t->sync_token);
				}
			}
		} else {
			if(active) {
				D("%s: transport got packet, sending to remote\n", t->serial);
				t->write_to_remote(p, t);
			} else {
				D("%s: transport ignoring packet while offline\n", t->serial);
			}
		}

		put_apacket(p);
	}

	// this is necessary to avoid a race condition that occured when a transport closes
	// while a client socket is still active.
	close_all_sockets(t);

	D("%s: transport input thread is exiting, fd %d\n", t->serial, t->fd);
	kick_transport(t);
	transport_unref(t);
	return 0;
}


static int transport_registration_send = -1;
static int transport_registration_recv = -1;
static fdevent transport_registration_fde;


#if ADB_HOST
static int list_transports_msg(char*  buffer, size_t  bufferlen)
{
	char  head[5];
	int   len;

	len = list_transports(buffer+4, bufferlen-4);
	sprintf(head,  "%04x", len);

	memcpy(buffer, head, 4);
	len += 4;
	return len;
}

/* this adds support required by the 'track-devices' service.
 * this is used to send the content of "list_transport" to any
 * number of client connections that want it through a single
 * live TCP connection
 */
typedef struct device_tracker  device_tracker;
struct device_tracker {
	asocket          socket;
	int              update_needed;
	device_tracker*  next;
};

/* linked list of all device trackers */
static device_tracker*   device_tracker_list;

static void device_tracker_remove( device_tracker*  tracker )
{
	device_tracker**  pnode = &device_tracker_list;
	device_tracker*   node  = *pnode;

	adb_mutex_lock( &transport_lock );
	while (node) {
		if (node == tracker) {
			*pnode = node->next;
			break;
		}
		pnode = &node->next;
		node  = *pnode;
	}
	adb_mutex_unlock( &transport_lock );
}

static void device_tracker_close( asocket*  socket )
{
	device_tracker*  tracker = (device_tracker*) socket;
	asocket*         peer    = socket->peer;

	D( "device tracker %p removed\n", tracker);
	if (peer) {
		peer->peer = NULL;
		peer->close(peer);
	}
	device_tracker_remove(tracker);
	free(tracker);
}

static int device_tracker_enqueue( asocket*  socket, apacket*  p )
{
	/* you can't read from a device tracker, close immediately */
	put_apacket(p);
	device_tracker_close(socket);
	return -1;
}

static int device_tracker_send( device_tracker*  tracker,
		const char*      buffer,
		int              len )
{
	apacket*  p = get_apacket();
	asocket*  peer = tracker->socket.peer;

	memcpy(p->data, buffer, len);
	p->len = len;
	return peer->enqueue( peer, p );
}


static void device_tracker_ready( asocket*  socket )
{
	device_tracker*  tracker = (device_tracker*) socket;

	/* we want to send the device list when the tracker connects
	 * for the first time, even if no update occured */
	if (tracker->update_needed > 0) {
		char  buffer[1024];
		int   len;

		tracker->update_needed = 0;

		len = list_transports_msg(buffer, sizeof(buffer));
		device_tracker_send(tracker, buffer, len);
	}
}


asocket* create_device_tracker(void)
{
	device_tracker*  tracker =(device_tracker*) calloc(1,sizeof(*tracker));

	if(tracker == 0) fatal("cannot allocate device tracker");

	D( "device tracker %p created\n", tracker);

	tracker->socket.enqueue = device_tracker_enqueue;
	tracker->socket.ready   = device_tracker_ready;
	tracker->socket.close   = device_tracker_close;
	tracker->update_needed  = 1;

	tracker->next       = device_tracker_list;
	device_tracker_list = tracker;

	return &tracker->socket;
}


/* call this function each time the transport list has changed */
void  update_transports(void)
{
	char             buffer[1024];
	int              len;
	device_tracker*  tracker;

	len = list_transports_msg(buffer, sizeof(buffer));

	tracker = device_tracker_list;
	while (tracker != NULL) {
		device_tracker*  next = tracker->next;
		/* note: this may destroy the tracker if the connection is closed */
		device_tracker_send(tracker, buffer, len);
		tracker = next;
	}
}
#else
void  update_transports(void)
{
	// nothing to do on the device side
}
#endif // ADB_HOST

typedef struct tmsg tmsg;
struct tmsg
{
	atransport *transport;
	int         action;
};

static int transport_read_action(int  fd, struct tmsg*  m)
{
	char *p   = (char*)m;
	int   len = sizeof(*m);
	int   r;

	while(len > 0) {
		r = adb_read(fd, p, len);
		if(r > 0) {
			len -= r;
			p   += r;
		} else {
			if((r < 0) && (errno == EINTR)) continue;
			D("transport_read_action: on fd %d, error %d: %s\n",
					fd, errno, strerror(errno));
			return -1;
		}
	}
	return 0;
}

static int transport_write_action(int  fd, struct tmsg*  m)
{
	char *p   = (char*)m;
	int   len = sizeof(*m);
	int   r;

	while(len > 0) {
		r = adb_write(fd, p, len);
		if(r > 0) {
			len -= r;
			p   += r;
		} else {
			if((r < 0) && (errno == EINTR)) continue;
			D("transport_write_action: on fd %d, error %d: %s\n",
					fd, errno, strerror(errno));
			return -1;
		}
	}
	return 0;
}

static void transport_registration_func(int _fd, unsigned ev, void *data)
{
	tmsg m;
	adb_thread_t output_thread_ptr;
	adb_thread_t input_thread_ptr;
	int s[2];
	atransport *t;

	if(!(ev & FDE_READ)) {
		return;
	}

	if(transport_read_action(_fd, &m)) {
		fatal_errno("cannot read transport registration socket");
	}

	t = m.transport;

	if(m.action == 0){
		D("transport: %s removing and free'ing %d\n", t->serial, t->transport_socket);

		/* IMPORTANT: the remove closes one half of the
		 ** socket pair.  The close closes the other half.
		 */
		fdevent_remove(&(t->transport_fde));
		adb_close(t->fd);

		adb_mutex_lock(&transport_lock);
		t->next->prev = t->prev;
		t->prev->next = t->next;
		adb_mutex_unlock(&transport_lock);

		run_transport_disconnects(t);
		// the free operation caused crash before.
#ifndef HAVE_WIN32_PROC
		if (t->product)
			free(t->product);
		if (t->serial)
			free(t->serial);

		memset(t,0xee,sizeof(atransport));
		free(t);
#endif
		update_transports();
		return;
	}

	/* don't create transport threads for inaccessible devices */
	if (t->connection_state != CS_NOPERM) {
		/* initial references are the two threads */
		t->ref_count = 2;

		if(adb_socketpair(s)) {
			fatal_errno("cannot open transport socketpair");
		}

		D("transport: %s (%d,%d) starting\n", t->serial, s[0], s[1]);

		t->transport_socket = s[0];
		t->fd = s[1];

		fdevent_install(&(t->transport_fde),
				t->transport_socket,
				transport_socket_events,
				t);

		fdevent_set(&(t->transport_fde), FDE_READ);

		if(adb_thread_create(&input_thread_ptr, input_thread, t)){
			fatal_errno("cannot create input thread");
		}

		if(adb_thread_create(&output_thread_ptr, output_thread, t)){
			fatal_errno("cannot create output thread");
		}
	}

	/* put us on the master device list */
	adb_mutex_lock(&transport_lock);
	t->next = &transport_list;
	t->prev = transport_list.prev;
	t->next->prev = t;
	t->prev->next = t;
	adb_mutex_unlock(&transport_lock);

	t->disconnects.next = t->disconnects.prev = &t->disconnects;

	update_transports();
}

void init_transport_registration(void)
{
	int s[2];

	if(adb_socketpair(s)){
		fatal_errno("cannot open transport registration socketpair");
	}

	transport_registration_send = s[0];
	transport_registration_recv = s[1];

	fdevent_install(&transport_registration_fde,
			transport_registration_recv,
			transport_registration_func,
			0);

	fdevent_set(&transport_registration_fde, FDE_READ);
}

/* the fdevent select pump is single threaded */
static void register_transport(atransport *transport)
{
	tmsg m;
	m.transport = transport;
	m.action = 1;
	D("transport: %s registered\n", transport->serial);
	if(transport_write_action(transport_registration_send, &m)) {
		fatal_errno("cannot write transport registration socket\n");
	}
}

static void remove_transport(atransport *transport)
{
	tmsg m;
	m.transport = transport;
	m.action = 0;
	D("transport: %s removed\n", transport->serial);
	if(transport_write_action(transport_registration_send, &m)) {
		fatal_errno("cannot write transport registration socket\n");
	}
}


static void transport_unref_locked(atransport *t)
{
	t->ref_count--;
	if (t->ref_count == 0) {
		D("transport: %s unref (kicking and closing)\n", t->serial);
		if (!t->kicked) {
			t->kicked = 1;
			t->kick(t);
		}
		t->close(t);
		remove_transport(t);
	} else {
		D("transport: %s unref (count=%d)\n", t->serial, t->ref_count);
	}
}

static void transport_unref(atransport *t)
{
	if (t) {
		adb_mutex_lock(&transport_lock);
		transport_unref_locked(t);
		adb_mutex_unlock(&transport_lock);
	}
}

void add_transport_disconnect(atransport*  t, adisconnect*  dis)
{
	adb_mutex_lock(&transport_lock);
	dis->next       = &t->disconnects;
	dis->prev       = dis->next->prev;
	dis->prev->next = dis;
	dis->next->prev = dis;
	adb_mutex_unlock(&transport_lock);
}

void remove_transport_disconnect(atransport*  t, adisconnect*  dis)
{
	dis->prev->next = dis->next;
	dis->next->prev = dis->prev;
	dis->next = dis->prev = dis;
}


atransport *acquire_one_transport(int state, transport_type ttype, const char* serial, char** error_out)
{
	atransport *t;
	atransport *result = NULL;
	int ambiguous = 0;

retry:
	if (error_out)
		*error_out = "device not found";

	adb_mutex_lock(&transport_lock);
	for (t = transport_list.next; t != &transport_list; t = t->next) {
		if (t->connection_state == CS_NOPERM) {
			if (error_out)
				*error_out = "insufficient permissions for device";
			continue;
		}

		/* check for matching serial number */
		if (serial) {
			if (t->serial && !strcmp(serial, t->serial)) {
				result = t;
				break;
			}
		} else {
			if (ttype == kTransportUsb && t->type == kTransportUsb) {
				if (result) {
					if (error_out)
						*error_out = "more than one device";
					ambiguous = 1;
					result = NULL;
					break;
				}
				result = t;
			} else if (ttype == kTransportLocal && t->type == kTransportLocal) {
				if (result) {
					if (error_out)
						*error_out = "more than one emulator";
					ambiguous = 1;
					result = NULL;
					break;
				}
				result = t;
			} else if (ttype == kTransportAny) {
				if (result) {
					if (error_out)
						*error_out = "more than one device and emulator";
					ambiguous = 1;
					result = NULL;
					break;
				}
				result = t;
			}
		}
	}
	adb_mutex_unlock(&transport_lock);

	if (result) {
		/* offline devices are ignored -- they are either being born or dying */
		if (result && result->connection_state == CS_OFFLINE) {
			if (error_out)
				*error_out = "device offline";
			result = NULL;
		}
		/* check for required connection state */
		if (result && state != CS_ANY && result->connection_state != state) {
			if (error_out)
				*error_out = "invalid device state";
			result = NULL;
		}
	}

	if (result) {
		/* found one that we can take */
		if (error_out)
			*error_out = NULL;
	} else if (state != CS_ANY && (serial || !ambiguous)) {
		adb_sleep_ms(1000);
		goto retry;
	}

	return result;
}

#if ADB_HOST
static const char *statename(atransport *t)
{
	switch(t->connection_state){
		case CS_OFFLINE: return "offline";
		case CS_BOOTLOADER: return "bootloader";
		case CS_DEVICE: return "device";
		case CS_HOST: return "host";
		case CS_RECOVERY: return "recovery";
		case CS_NOPERM: return "no permissions";
		default: return "unknown";
	}
}

int list_transports(char *buf, size_t  bufsize)
{
	char*       p   = buf;
	char*       end = buf + bufsize;
	int         len;
	atransport *t;

	/* XXX OVERRUN PROBLEMS XXX */
	adb_mutex_lock(&transport_lock);
	for(t = transport_list.next; t != &transport_list; t = t->next) {
		const char* serial = t->serial;
		if (!serial || !serial[0])
			serial = "????????????";
		len = sprintf(p, "%s\t%s\n", serial, statename(t));


		if (p + len >= end) {
			/* discard last line if buffer is too short */
			break;
		}
		p += len;
	}
	p[0] = 0;
	adb_mutex_unlock(&transport_lock);
	return p - buf;
}


/* hack for osx */
void close_usb_devices()
{
	atransport *t;

	adb_mutex_lock(&transport_lock);
	for(t = transport_list.next; t != &transport_list; t = t->next) {
		if ( !t->kicked ) {
			t->kicked = 1;
			t->kick(t);
		}
	}
	adb_mutex_unlock(&transport_lock);
}
#endif // ADB_HOST

void register_socket_transport(int s, const char *serial, int port, int local)
{
	atransport *t =(atransport *) calloc(1, sizeof(atransport));
	char buff[32];

	if (!serial) {
		sprintf(buff,  "T-%p", t);

		serial = buff;
	}
	D("transport: %s init'ing for socket %d, on port %d\n", serial, s, port);
	if ( init_socket_transport(t, s, port, local) < 0 ) {
		adb_close(s);
		free(t);
		return;
	}
	if(serial) {
		t->serial = strdup(serial);
	}
	register_transport(t);
}

#if ADB_HOST
atransport *find_transport(const char *serial)
{
	atransport *t;

	adb_mutex_lock(&transport_lock);
	for(t = transport_list.next; t != &transport_list; t = t->next) {
		if (t->serial && !strcmp(serial, t->serial)) {
			break;
		}
	}
	adb_mutex_unlock(&transport_lock);

	if (t != &transport_list)
		return t;
	else
		return 0;
}

void unregister_transport(atransport *t)
{
	adb_mutex_lock(&transport_lock);
	t->next->prev = t->prev;
	t->prev->next = t->next;
	adb_mutex_unlock(&transport_lock);

	kick_transport(t);
	transport_unref(t);
}

// unregisters all non-emulator TCP transports
void unregister_all_tcp_transports()
{
	atransport *t, *next;
	adb_mutex_lock(&transport_lock);
	for (t = transport_list.next; t != &transport_list; t = next) {
		next = t->next;
		if (t->type == kTransportLocal && t->adb_port == 0) {
			t->next->prev = t->prev;
			t->prev->next = next;
			// we cannot call kick_transport when holding transport_lock
			if (!t->kicked)
			{
				t->kicked = 1;
				t->kick(t);
			}
			transport_unref_locked(t);
		}
	}

	adb_mutex_unlock(&transport_lock);
}

#endif

void register_usb_transport(usb_handle *usb, const char *serial, unsigned writeable)
{
	atransport *t = (atransport *)calloc(1, sizeof(atransport));
	D("transport: %p init'ing for usb_handle %p (sn='%s')\n", t, usb,
			serial ? serial : "");
	init_usb_transport(t, usb, (writeable ? CS_OFFLINE : CS_NOPERM));
	if(serial) {
		t->serial = strdup(serial);
	}
	register_transport(t);
}

/* this should only be used for transports with connection_state == CS_NOPERM */
void unregister_usb_transport(usb_handle *usb)
{
	atransport *t;
	adb_mutex_lock(&transport_lock);
	for(t = transport_list.next; t != &transport_list; t = t->next) {
		if (t->usb == usb && t->connection_state == CS_NOPERM) {
			t->next->prev = t->prev;
			t->prev->next = t->next;
			break;
		}
	}
	adb_mutex_unlock(&transport_lock);
}

#undef TRACE_TAG
#define TRACE_TAG  TRACE_RWX

int readx(int fd, void *ptr, size_t len)
{
	char *p =(char *) ptr;
	int r;
#if ADB_TRACE
	int  len0 = len;
#endif
	D("readx: fd=%d wanted=%d\n", fd, (int)len);
	while(len > 0) {
		r = adb_read(fd, p, len);
		if(r > 0) {
			len -= r;
			p += r;
		} else {
			if (r < 0) {
				D("readx: fd=%d error %d: %s\n", fd, errno, strerror(errno));
				if (errno == EINTR)
					continue;
			} else {
				D("readx: fd=%d disconnected\n", fd);
			}
			return -1;
		}
	}

#if ADB_TRACE
	D("readx: fd=%d wanted=%d got=%d\n", fd, len0, len0 - len);
	dump_hex( (unsigned char *)ptr, len0 );
#endif
	return 0;
}

int writex(int fd, const void *ptr, size_t len)
{
	char *p = (char*) ptr;
	int r;

#if ADB_TRACE
	D("writex: fd=%d len=%d: ", fd, (int)len);
	dump_hex( (const unsigned char *)ptr, len );
#endif
	while(len > 0) {
		r = adb_write(fd, p, len);
		if(r > 0) {
			len -= r;
			p += r;
		} else {
			if (r < 0) {
				D("writex: fd=%d error %d: %s\n", fd, errno, strerror(errno));
				if (errno == EINTR)
					continue;
			} else {
				D("writex: fd=%d disconnected\n", fd);
			}
			return -1;
		}
	}
	return 0;
}

int check_header(apacket *p)
{
	if(p->msg.magic != (p->msg.command ^ 0xffffffff)) {
		D("check_header(): invalid magic\n");
		return -1;
	}

	if(p->msg.data_length > MAX_PAYLOAD) {
		D("check_header(): %d > MAX_PAYLOAD\n", p->msg.data_length);
		return -1;
	}

	return 0;
}

int check_data(apacket *p)
{
	unsigned count, sum;
	unsigned char *x;

	count = p->msg.data_length;
	x = p->data;
	sum = 0;
	while(count-- > 0) {
		sum += *x++;
	}

	if(sum != p->msg.data_check) {
		return -1;
	} else {
		return 0;
	}
}

